Draw on coach batts, 2010 Baystar

[HMXDave]

I have a post going in the "RV systems and appliances" forum regarding batteries going dead on my new (still unused) BayStar. As the dealer is over an hour away, I brought the batteries to them for testing. They assure me that the batteries are fine. Thought I would post here and inquire as to what might be drawing these things down. The batts are 2 Interstate group 24 12v wired in parallel. I took a pic before removing them and it appears there are three main cables "feeding" off these batts. I am assuming that one is the coach power, one is to the "battery boost" for the chassis, and one is to the inverter. After three days of charging with the converter (I never had the IQ Smart Charge at the time....have it now) the batts would show 12.7 volts after resting a few hours, then down to 11.7 or less after 2 days. This is with the main power turned OFF and nothing running.

Does the inverter draw juice even when the remote switch is OFF? There is a switch on the inverter itself that remains on....but I leave the remote deal inside the coach OFF.

According to the Newmar manual, the only thing that recieves power when the main power solonoid is OFF, is the LP detector. Is it possible that the main power solonoid is drawing power?

Any other ideas before I book an appointment for warrantee. (then of course they will find nothing and I will be out the time and the fuel and still have a problem)

[94-Newmar]

I always question a shop's ability to test batteries. You don't know if they simply used a voltmeter or a quality battery load tester. In a parallel system if one battery has a failing or shorted cell it will draw from the others in the pair.

I know this sounds crazy.. but are you absolutely sure there are no 12v lights in a closed compartment that may have been left on? Any 12v plug-in devices you may have left plugged in somewhere? If not.. then...

I would start troubleshooting by simply disconnecting anything connected to the negatives on the battery pair and seperate the parallel. Tape the leads/cables up and move them aside.

Use your voltmeter and check the voltage on each battery individually.
Are they even in voltage?
Wait 24 hrs, check them again, are they still even?
How much did they/each lose in 24 hrs?

If you're handy enough with the voltmeter you can check for resistance from any of the neg to pos leads to see if there is any draw at all on them. IF your systems are truly turned off and not drawing anything you should see 0 resistance between them. (batteries disconnected obviously)

You may have to go thru and manually disconnect certain circuits to find if anything is drawing your batteries down IF the batteries prove to be OK. It's always a pain in the butt hunting down electrical gremlins but there is no easy or shortcut way to do it.

Keep us posted!

["007"]

I would charge your batteries with a good 12V battery charger it will be quicker than your inverter or converter charge.
Takes to long with Gen or just inverter charge to bring them back up to full charge.
If you have 110V outlet near your coach in storage with shore line plugged in your B.I.R.D. System should maintain all your batteries.
The LP detector is off your engine starter battery and I have a switch in panel display to shut it off during storage.
My batteries are charged all winter with coach plugged into house outlet never had dead batteries on three Newmars.
With all appliances shut off you should not be drawing that much off your batteries.
Do as 94 says and charge batteries and check them after charge if one of your batteries has a short its going to cause a problem with the other.
May want to just charge individually and see if it wholes a charge.

[HMXDave]

Thanks gents. I will be retriving the batts this afternoon....I will get them on the bench and monitor/charge for a few days before I put them back in. (assuming they're OK) I actually understood most of 94's suggested testing proceedures, so if the batts check out, I will go to work with the multi-meter.

[GaryKD]

Hi HMXDave,
I'd do the testing a bit differently. Being the lazy guy I am, I try the quick and simple stuff first. Based on your previous post, you're going to pull the batts and put them in a warm area. I notice your in Canada, you probably know cold and batteries do not go together. Here's what I'd do.

1. Get the batts in a warm area.
2. Charge them with a good smart charger for a couple of days.
3. While the batts are charging purchase a hydrometer. Any auto parts store will have them.
4. Once the batts have charged for a couple of days, disconnect the charger and let the batteries sit for about 6 to 8 hours +/-. This gets rid of a surface charge.
5. Using the hydrometer, take a reading on each cell and write it down.
All the cells should be very close to the same reading (=/- .05). This is one time one can be thankful one has flooded cell batts.
6. If not, there is a bad cell.
7. Specific Gravity readings are:
State of Charge Specific Gravity Voltage
12V Battery
100%1.265
75% 1.225
50% 1.190
25% 1.155
Discharged 1.120

8. With a meter take a VDC reading. It should be 12.6 or greater.
9. If you do not have one, purchase a battery load tester. With vehicles and a coach, batteries are going to be a larger part of your life than you want. A load tester of 100 AMPs or greater is what is needed.
10. When the batts are fully charged, load test them.

All the above can be done while the batts are on your bench, with a single full charge and not much time spent. If all checks out, then you can be assured the batts are okay. The tools purchased now will be used many times during your coach ownership.

It is time to look at the coach.
11. Reinstall the batts.
12. Turn everything off, LP detector, master coach store switch, inverter, triple check everything is off. Don't forget the basement compartment lights.
13. Your VOM should have the capability to measure AMP draw. If it does not, purchase a meter with clamp on AMP draw capability.
14. Measure the AMP draw on the batts.
15. If there is a draw, per the previous posts, start pulling fuses from the 12 VDC panel until the draw goes away. You now have the offending circuit.

Gut feel says the biggest problem is the cold. I will not mess with a battery problem until the batts (themselves, not just the air temp) are at least 60 degrees F.

[Iron Man]

The inverter will stay on unless you turn it off. The house battery disconnect does not turn off the inverter.

[TW]

I have the same problem. They just hold for about 3-4 days around 11.9 - 11.8
Since our RV Parkingspot with power is not ready, I go for a drive or let the GEN run for an hour every 2 weeks. I switch to 2 6V
Main switch will be turned OFF, when I leave the coach.
I'm used to keep an eye on the BATT
Next week the driving summer starts

TW